Vehicle suspension systems include resilient devices configured to absorb forces such as road shock and other vibrations while providing a smooth and comfortable ride for vehicle occupants. Such devices may include springs, such as coil springs, leaf springs, torsion bars, etc. configured to store such forces by compression and/or extension, and dampers configured to dissipate the forces by dampening oscillation of the springs. Parameters such as spring rate of the springs and damping forces, such as compression damping, i.e., the damping force acting against compression of the spring, and rebound damping, i.e., the damping force acting against extension of the spring, and other parameters and characteristics are chosen as a compromise between occupant comfort and chassis stability under, e.g., high-speed or emergency maneuvers.
Suspension systems may include control systems configured to recognize irregularities (e.g., potholes, bumps, etc.) in a surface to be traversed by the vehicle, and adjust suspension characteristics based on the location and size of the irregularity to provide a more comfortable ride. For example, such systems may include optical or radar detectors that map the surface, and may soften a compression damping force of a damper of the suspension system as the vehicle approaches the irregularity to provide a more comfortable ride for the vehicle occupants. However, if the vehicle encounters a series of repeated irregularities with a substantially regular frequency, the suspension system may not adjust in a manner that effectively absorbs the forces generated as the vehicle travels over the irregularities. It may be desirable to provide a suspension system that is able to effectively absorb forces as encountered regardless of the timing between occurrences.